Interest is money the bank pays you for letting them use your deposits

When you put money in a savings account, the bank lends that money to other customers through mortgages, car loans, and business lines of credit. The bank keeps the difference between what it pays you and what it charges borrowers. That payment to you is interest—usually a small percentage of your balance, paid monthly or daily depending on the account.

The amount you earn depends on three things: how much money sits in the account, how long it stays there, and the interest rate the bank offers. A $10,000 balance at 4.5% annual interest earns roughly $450 per year. The same balance at 0.01% earns 50 cents. The difference between those two rates is real and measurable—it matters which account you choose.

Interest rates change. Banks raise them when the Federal Reserve raises its benchmark rate, and lower them when the Fed cuts. Your rate can also change if you move money to a different account or bank. Some accounts lock in a fixed rate for a set period; others adjust whenever the bank decides.

Key Takeaways

  • Banks pay interest on savings accounts because they lend your deposits to other customers and share part of the profit with you.
  • The interest rate varies by bank and account type—high-yield savings accounts currently pay roughly 4% to 5%, while traditional savings accounts often pay less than 0.5%.
  • Interest compounds, meaning you earn interest on your interest, so money that sits untouched grows faster over time.
  • The Federal Reserve's interest rate decisions affect what banks offer, so rates rise and fall throughout the year.

How the interest rate is set and what affects it

Banks set their own interest rates, but they follow the federal funds rate—the interest rate the Federal Reserve charges banks to borrow from each other. When the Fed raises its rate, banks typically raise what they offer on savings accounts. When the Fed cuts, banks cut their rates.

Competition also matters. If one bank offers 4.5% on savings and another offers 0.5%, customers move their money to the higher rate. Banks that want to keep deposits have to match or come close. Online banks often offer higher rates than brick-and-mortar banks because they have lower overhead costs and can afford to pay more.

The type of account changes the rate too. A high-yield savings account pays more than a regular savings account at the same bank. A money market account may pay more than either, but usually requires a higher minimum balance. A certificate of deposit (CD) locks your money away for a set term—three months, one year, five years—and pays a fixed rate that is often higher than savings accounts because the bank knows exactly how long it can lend your money.

How interest compounds and grows your balance

Banks calculate interest on your balance and add it to your account. The next time they calculate interest, they calculate it on the new, larger balance—including the interest you just earned. This is called compounding, and it means your money grows faster the longer it sits.

The timing matters. Some banks compound interest daily, some weekly, some monthly. Daily compounding grows your balance slightly faster than monthly because you earn interest on your interest more often. Over a year, the difference between daily and monthly compounding on a $10,000 balance at 4% is roughly $10 to $15—small but real.

A concrete example: $10,000 at 4% annual interest compounded daily grows to about $10,408 after one year. The same $10,000 at 4% compounded monthly grows to about $10,407. The difference widens over longer periods. After five years, daily compounding reaches roughly $12,214, while monthly reaches $12,210. The longer your money stays in the account, the more compounding works in your favor.

The difference between fixed and variable rates

A fixed rate stays the same for the entire time you hold the account or CD. If you open a one-year CD at 4.5%, you earn 4.5% for the full year no matter what the Fed does. This protects you if rates fall, but it also means you miss out if rates rise.

A variable rate changes when the bank changes it. Most savings accounts and money market accounts have variable rates. The bank can lower your rate whenever it wants, though it usually does so only when the Fed cuts its rate. If rates rise, your bank may raise your rate, but it is not required to match competitors—you have to move your money to a higher-paying account to benefit.

CDs lock you in for a set term, so the rate is fixed for that period. If you withdraw the money early, you pay a penalty—usually a few months of interest. If rates rise after you open the CD, you are stuck at the lower rate unless you pay the penalty and move the money. If rates fall, you are protected by your higher locked-in rate.

Where to find the best rates right now

High-yield savings accounts at online banks currently pay between 4% and 5.35% annual interest, though this changes as the Fed adjusts rates. Traditional savings accounts at large brick-and-mortar banks often pay 0.01% to 0.5%. The difference is substantial: $10,000 in a high-yield account earning 4.5% grows to $10,450 in a year, while the same amount in a 0.01% account grows to $10,001.

Money market accounts at online banks typically pay similar rates to high-yield savings accounts, usually between 4% and 5%. CDs vary by term and bank. A one-year CD might pay 4.5% to 5%, while a five-year CD might pay 4% to 4.75%, depending on where rates are headed.

Comparison sites like Bankrate, DepositAccounts, and NerdWallet list current rates across banks and update them regularly. Your own bank's website shows what it is currently offering. Rates change frequently, so checking once a month helps you decide whether to move money or open a new account.

How taxes affect the interest you keep

Interest income is taxable. If you earn $450 in interest during a year, you owe federal income tax on that $450 at your regular tax rate. Some states also tax interest income. The bank will send you a 1099-INT form in January showing how much interest you earned, and you report that on your tax return.

This means the interest you actually keep is less than the interest rate suggests. If you earn $450 in interest and your tax rate is 22%, you owe roughly $99 in taxes, leaving you with $351. The higher your tax bracket, the more of your interest goes to taxes.

Tax-advantaged accounts like IRAs and 401(k)s let interest compound without annual taxes, though you pay taxes when you withdraw the money in retirement. For regular savings accounts, there is no way around the tax—it is owed on the interest earned each year.

What happens if you withdraw money before interest is paid

Most banks calculate and deposit interest monthly, so if you withdraw money mid-month, you still receive the interest earned up to that point. Some banks calculate daily, so you earn interest right up until the withdrawal. Check your account terms to see when interest is credited.

The main exception is CDs. If you withdraw from a CD before the term ends, you pay an early withdrawal penalty. This penalty is usually stated as a number of months of interest. A one-year CD with a three-month penalty means if you withdraw after six months, you lose three months of interest—even if you have already earned more than that. This can mean you withdraw less than you deposited if rates have fallen significantly.

Savings accounts and money market accounts have no early withdrawal penalty, so you can take your money out whenever you want without losing interest.

Frequently Asked Questions

Do I have to do anything to earn interest, or does it happen automatically?

Interest happens automatically. Once you open the account and deposit money, the bank calculates and adds interest on its schedule—usually monthly or daily. You do not need to take any action. The interest appears in your account balance.

Can I lose money if interest rates fall?

No. Interest rates falling means the bank will pay you less interest going forward, but you do not lose what you have already earned. Your balance stays the same; future interest payments are just smaller. The only exception is if you locked money in a CD at a high rate and rates fall—you are stuck earning the higher rate, which is actually good for you.

Is there a minimum balance required to earn interest?

It depends on the account. Some savings accounts require a minimum balance—often $500 to $2,500—to earn the advertised interest rate. If your balance falls below the minimum, you earn a lower rate or no interest. High-yield savings accounts often have no minimum. Check your account terms or ask the bank before opening.

How often should I move my money to chase higher rates?

Moving money costs time and attention but not money—there are no fees for transferring between banks. If your current account pays 0.5% and another bank pays 4.5%, moving makes sense. If your current account pays 4.4% and another pays 4.5%, the difference is small enough that moving is optional. Most people move once or twice a year when rates change significantly.

What is the difference between APY and APR on a savings account?

APY (annual percentage yield) includes the effect of compounding and shows what you actually earn over a year. APR (annual percentage rate) is the interest rate without compounding. Banks advertise APY for savings accounts because it is the real number. A 4% APY account earning daily interest actually pays slightly more than 4% APR because of compounding.